Alkaline phosphatase activity after cardiothoracic surgery in infants and correlation with post-operative support and inflammation: a prospective cohort study
Critical Care, 08/21/2012
Davidson J et al. – Alkaline phosphatase activity decreases after cardiothoracic surgery in infants. Low post–operative alkaline phosphatase activity is independently associated with increased procalcitonin, increased vasoactive/inotropic support, prolonged intubation time, and prolonged hospital stay. Alkaline phosphatase may serve as a biomarker and potential modulator of post–operative support and inflammation following cardiothoracic surgery in infants.Methods
- Sub–analysis of a prospective observational study on the kinetics of procalcitonin in 70 infants ([less than or equal to]90days old) undergoing cardiothoracic surgery.
- Subjects were grouped based on the use of cardiopulmonary bypass and delayed sternal closure.
- Alkaline phosphatase, procalcitonin, and C–reactive protein (CRP) levels were obtained pre–operation and on post–operative day 1.
- Mean change in alkaline phosphatase activity was determined in each surgical group.
- Generalized linear modeling and logistic regression were employed to assess for associations between post–operative alkaline phosphatase activity and post–operative support, inflammation, and short term outcomes.
- Primary endpoints were vasoactive–inotropic score at 24hours and length of intubation.
- Secondary endpoints included procalcitonin/CRP levels on post–operative day 1, length of hospital stay, and cardiac arrest or death.
- Mean decrease in alkaline phosphatase was 30U/L (p=0.01) in the non–bypass group, 114U/L (p<0.0001) in the bypass group, and 94U/L (p<0.0001) in the delayed sternal closure group.
- On multivariate analysis, each 10U/L decrease in alkaline phosphatase activity on post–operative day 1 was independently associated with an increase in vasoactive–inotropic score by 0.7 (p<0.0001), intubation time by 6% (p<0.05), hospital stay by 5% (p<0.05), and procalcitonin by 14% (P<0.01), with a trend towards increased odds of cardiac arrest or death (OR 1.3; p=0.06).
- Post–operative alkaline phosphatase activity was not associated with CRP (p=0.7).